Sounds if you should, and this is a should have a HP advantage. The 5.0 is stout but it sounds like it will come down to the drivers and gear selections. There are still plenty of variables in the outcome. You should win this one but like I said you are close in numbers by assumption.

I ended up going with a 5.0 on my way home from work last week. At the time I was completely stock(only had the car 2 weeks now) and the 5.0 couldnt get away. He would pull but not by much maybe a car, car and a half. Keep in mind these were highway speeds going from 65+ if it were from 40 it would be even closer since the weight plays a bigger roll the slower your moving.

I now have jb4 running e85/93 mix and with how much harder the car pulls I think I would have pulled quite hard that mustang. you are just about FBO, a stock 5.0 with exhaust should be a total cakewalk for you.

I have an N55 and with JB4, downpipe, and intake and I pulled on a 5.0 from 50-150...but at around 150 he started passing

Dont under estimate the 5.0. I sell them for a living, that motor and transmission have so much potential its scary. In stock form they are strong when boosted they are borderline funny how much they handle with just adding a blower. I like the drive of my 335 coupe, I like the power now that Im jb4 of my coupe, I like the grunt off the line of the Mustang more. One day Im sure I will buy one, but for now you have to work to keep them down!